This invention relates to a substrate managing or controlling system for handling a substrate (plate-like article) such as a photomask, a reticle, a wafer or a glass plate, for example. Further, the invention is concerned with a substrate container or a substrate storing system for storing such substrate or substrates therein, or a device manufacturing method or an exposure apparatus using such managing system, storing system or container. More specifically, the invention is directed to reading information, such as identification information, for example, as recorded on a substrate by printing, for example, and to controlling conveyance or handling of the substrate in accordance with the information.
Generally, semiconductor device manufacturing apparatuses use a substrate conveying system for automatically conveying a reticle, or a cassette or carrier (hereinafter xe2x80x9ccassettexe2x80x9d) within the apparatus or between different device manufacturing apparatuses, for prevention of adhesion of foreign particles to a substrate such as a reticle or a wafer (hereinafter, xe2x80x9csubstratexe2x80x9d), for example, or for improved productivity.
In such substrate conveying system, for correct selection of a desired reticle necessary for a particular production process and for quick supply of the same, and for reticle management and handling with higher reliability, a code with a pattern which bears information related to that reticle is printed on a peripheral portion of the substrate, the code being read out in each process or in each apparatus for data collection, registration, identification or confirmation.
On the other hand, due to recent tendency of multiplication of types of LSIs or complication of processes resulting from improvement in performance and reduction in size that causes increases in number of reticles required, the data volume of the code to be printed is increasing.
Also, due to recent tendency of multiplication of types of LSIs or complication of processes resulting from improvement in performance and reduction in size that causes increases in number of reticles required, higher reliability is required for reticle management and handling. A code may be printed on a reticle itself, and the code may be read out inside the apparatus and just before the reticle is used, for final identification and confirmation.
If information is to be recorded on a substrate, in order to attain enlargement of information volume of the reticle data, a large area is required for a code pattern to bear the information. However, on the reticle surface, there are a circuit pattern to be used for manufacture of semiconductor devices, as well as marks such as alignment marks to be used for different exposure processes in different exposure apparatuses. Thus, if the area of code pattern is enlarged, it will cause a difficulty in code layout design to prevent interference with marks on the reticle surface. Also, to prevent interference with marks, as an example, a code has to be divided into plural regions. This creates complexity in reading the code.
In a reticle storing system or a substrate storing shelf inside or outside an exposure apparatus, usually plural substrates are stored in accumulation along a vertical direction. Thus, the code reading when a particular substrate is to be used has to be done after the substrate is once taken out of the storing shelf.
Reticle cassettes or reticle carriers have no optical transparency, and an information code on a reticle can not be read directly. For this reason, a substitute code is printed on a cassette and, by using this substitute code, data collection or registration for the reticle stored inside the cassette is carried out. This necessitates strict control or handling to hold the one-on-one relation between a cassette and a reticle. In that occasion, when the reticle and the cassette are placed separate for cleaning of the reticle or cassette, there is a possibility of occurrence of incorrect mating of cassette reticle, which degrades reliability of reticle management and handling.
A code printed on a reticle itself is used for final identification and confirmation. If incorrect combination of a reticle and a cassette occurs, since the reticle registration is made on the basis of a code as printed on the cassette, the error can not be detected until the reticle is loaded into the apparatus and the code printed on the reticle is read just before it is used. Then, the reticle is unloaded to be replaced. This damages efficient substrate conveyance.
It is accordingly an object of the present invention to provide higher reliability and efficiency in processing a substrate.
In accordance with an aspect of the present invention, there is provided a substrate managing or controlling system, comprising: reading means for reading information recorded on a substrate; and information processing means for performing management of the substrate on the basis of the information; wherein said reading means reads information as recorded on an end face of the substrate.
With this arrangement, it is unnecessary to take into account the disposition of alignment marks upon a substrate surface, for example, and the whole region of the end face of the substrate can be used for the recording of substrate information. As a result, an enlargement of recording region due to an enlargement in number or type of substrates can be easily met. Further, even in an occasion where substrates are stored while being accumulated in vertical direction, information reading can be done while the substrates are kept stored. This enables flexible and multifarious control of substrates.
In accordance with another aspect of the present invention, there is provided a substrate container wherein at least a portion of said container is made of a transparent material for optical reading of information as recorded on a substrate kept stored in the container. In a substrate managing method according to the present invention, the information of a substrate stored in such substrate container can be read through the transparent material member.
With this structure, the information about the substrate can be read while the substrate is kept stored in the container. Thus, there is no necessity of recording information on the substrate container. Also, it is unnecessary to control the information as recorded on the substrate container and the information about the substrate in one-on-one relation. Further, without reading the information as recorded on the substrate container (as has been done conventionally) and collecting information about the substrate as stored in the container, the information about the substrate can be read directly. As a result, any error of substrate selection, for example, can be detected at an earlier stage and thus efficient and reliable substrate control, substrate conveyance and device manufacture are assured.
In a preferred form, the substrate may be a photomask, a reticle or a wafer to be used in an exposure apparatus. The information recorded on a substrate may be one which can be read optically, such as a bar code, for example.
The information processing means may set parameters, necessary for performing a process related to the substrate, in accordance with the information.
The reading means may read the information of the substrate in a portion of a conveyance path including a conveyance start position and a conveyance completion position.
There may be plural substrates stored in an array in a direction perpendicular to the surface of each substrate, and said reading means may read the information of a desired substrate as kept stored, during relative movement between a reading position of the reading means and the plural substrates stored.
The reading means may include rotating means for rotating the substrate in a horizontal plane, and wherein said reading means reads the recorded information as desired end faces of the rotated substrate are positioned at a reading position of the reading means.
When at least a portion of the substrate container is made of a transparent material, the information about the substrate may be recorded on an end face of the substrate.
When at least a portion of the substrate container is made of a transparent material, the information about the substrate as stored in the container may be read through the transparent material. In such case, the information reading may be done by use of a light projecting device disposed at a side of said container and a light detecting device for detecting light projected and passed a portion of the substrate where the information is recorded. The information reading may be done in a portion of a conveyance path including a conveyance start position and a conveyance completion position.
A substrate managing system or a substrate storing system such as:described above may be incorporated into an exposure apparatus.
Where a substrate comprises an original having a pattern to be exposed, there may be provided a device manufacturing method wherein information recorded on an end face of the original is read, or information of the original is read through a transparent portion of a container in which the original is stored, and the pattern of the original is printed onto a workpiece to be exposed, on the basis of the information.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.